Sunday, December 10, 2006

Livestock Bigger Contributor to Global Warming than Transportation

There's a new UN report out on climate change, and it comes to all sorts of interesting conclusions. I'll be dealing with one of them in a post for Treehugger and Seventh Generation's Convenient Truths contest on Tuesday Wednesday (maybe), but another one that will raise plenty of eyebrows concerns the role of livestock in contributing to rising levels of greenhouse gas emissions. Now, if you're expecting news on cow farts, you're going to get it... but the issue is more complex. According to the Jackson, Mississippi, Clarion-Ledger:

When it comes to global warming, there are bigger culprits than the car: Cattle, pigs and chickens.

So says a new report from the United Nations Food and Agriculture Organization. The report estimates that the livestock production worldwide is responsible for 18 percent of greenhouse gas emissions, more than the transportation sector produces.

The estimate for the livestock sector includes everything from the gases emitted when nitrogen fertilizer is applied to feed crops like corn, the carbon losses from cutting down forests for farms to the methane released by the animals' manure.

Livestock production accounts for 65 percent of the human-related emissions of nitrous oxide, a result of using nitrogen fertilizer. Nitrous oxide has 296 times the global warming potential of carbon dioxide.

The report also notes that this finding shows the difference between developing world greenhouse gas emissions (where livestock contributions are higher) and those of developed countries (in the US, fossil fuels are a bigger culprit than cows). Does this mean a vegetarian diet is more climate friendly? Yes, but the C-L also points to initiatives underway to combat this challenge with the current size of livestock herds. One of the most far-reaching (in my humble opinion) may be increased use of methane digesters: cut the emissions, and get energy in the bargain. Reforestation is another big move -- obviously, this gives further incentive for better management of forests that are still standing around the world. Finally, I don't think this should be read as undermining moves towards more efficient and less polluting transportation options -- that's still an issue, particularly in the Northern Hemisphere.